Two of nature's most menacing forces, a tornado and lightning

Double trouble — lightning and a waterspout — is spawned by a June storm over Florida's Lake Okeechobee. Over land, severe thunderstorms are the major source of tornadoes. Bernard, Vonnegut, a researcher at New York's University at Albany, says the most powerful tornadoes may get their boost from a thunderstorm's electric energy. Other scientists also suspect a link between tornadoes and electricity: Lightning activity often increases or drops dramatically just before a violent tornado forms.